is no longer supported. In practice this pattern was never used. Typical event handlers are interested in all changes to a given attribute. Some particular change to some particular attribute was too fine grained a filtering for general use and the over all gains of the new strategy where deemed to outweigh the usefulness of this unused pattern.

For testing attribute names within event handler implementations you should continue to use the attribute constants such as

UIEvents.UILabel.LABEL

as these are the values inserted into the UI Events by UIEventPublisher